Field of the Invention
The present invention relates to an adjustable vertical pipe support, in which a second saw-toothed portion is positioned in a wedge of a length adjusting member for adjusting a length of upper and lower pipes, so as to prevent unlocking or slip of the upper pipe and thus improve the safety of the vertical pipe support, even though a first rotation adjustor is rotated by a tensile force or an external force.
Background of the Related Art
Recently, there has been a string of industrial accidents due to breaking of temporary pipe supports and scaffolds. In particular, the accidents usually happen in the process of installing or uninstalling the pipe supports which are widely used for slabs of reinforced concrete structures.
A pipe support 1 of the related art illustrated in FIG. 1 includes an upper pipe 30 having a plurality of holes 31, a lower pipe 20 having an elongated hole 21, a locking pin 10 inserted in any one of the holes 31 formed in the upper pipe 30, and a length adjusting nut 40 threadedly engaging to the lower pipe 20 to support the locking pin 10 and adjust the height of the pipe support 1 by rotation thereof.
However, the pipe support 1 of the related art has a problem in that since the upper pipe 30 and the lower pipe 20 are perforated, the pipes suffer a loss in cross section. In particular, the pipe supports 1, to which a compressive force is applied, are very vulnerable to buckling, if a portion of the cross section is damaged or broken.
In addition, since any gap is formed between an outer diameter of the upper pipe 30 and an inner diameter of the lower pipe 20, the upper pipe 30 is not firmly locked to the lower pipe 20. Thus, when the compressive force is applied to the pipe support, the pipe support 1 is applied by an eccentric load, so that the pipe support 1 may be deflected. As the length of the pipe support 1 is long, the pipe support 1 will not properly support an allowable load.
Also, since the length adjusting nut 40 is positioned below the locking pin 10, and supports the load applied from the top, the length adjusting nut 40 does not withstand a tensile force.
As illustrated in FIG. 2, Korea Patent No. 10-0979817 discloses a pipe support for construction, in which an upper pipe 20 is locked by stoppers 110 and 120 so as to stably and firmly support the load.
In general, since temporary pipe supports are not permanently fixed, an unexpected tensile force may be applied to the pipe supports by lateral loads, wind loads, or work impact loads to be generated when the pipe supports are installed, uninstalled, or retained.
According to the pipe support disclosed in the patent, if the outer stopper 120 is rotated in an opposite direction by the tensile load or the external impact, the upper pipe 20 immediately comes out from the inner stopper 110, and thus the upper pipe is unlocked, which causes the industrial accident.
Also, in case of system scaffolds, of which girders, struts and braces are prefabricated at a plant and then are assembled on the spot, the tensile force is generated from any members according to load conditions. The pipe support cannot be used due to risks of collapse when the tensile force is generated.
When the pipe support is assembled, the upper pipe 20 is inserted into or pulled out from the lower pipe 10, and then is approximately locked. After that, the height of the pipe support should be set by minutely adjusting in order to level an upper member. However, the pipe support disclosed in the patent is difficult to adjust the height of the pipe support since the fine adjustment is impossible after the position of the upper pipe 20 is locked.